The 5 V DC power needed for the microprocessor system and as control current for the I/O modules is generated from the 24 V DC power of the system via clocked 24 V DC / 5 V DC power supply modules bearing the F 7126 identification. One central rack can be equipped with a maximum of 3 power supply modules. The power supply modules are switched in parallel. One or two power supply modules are usually able to supply the PES. A further power supply module is used to increase availability.
